Linum grandiflorum aka Crimson Flax

Linum grandiflorum is an annual in the flax family, Linaceae. Its common names include flowering flax and scarlet flax. Garden annual flax is another name. The sources disagree on its native range. NC State lists Turkey, Syria, and Iran as its origins. RHS instead lists the United States and Canada. NC State says people have brought it to several other world regions. It says plants may live longer in Turkey. In most gardens, they last for just one season.

Plants have straight stems that branch as they grow. RHS gives a garden height of about 1.6 feet (0.5 metres). Its listed spread reaches about 0.3 feet (0.1 metres). Small green leaves line the stems and have a waxy surface. Each leaf is simple, with one blade. Its lanceolate shape is narrow and tapers to a point. The edges are smooth. The leaves lack hairs and measure less than an inch long. NC State rates growth as moderate and care needs as low.

Loose groups of flowers rise above the narrow leaves. Their open, saucer-like shape makes them easy to see. The sources give shades from rose pink to deep red. RHS notes dark centres. NC State describes black edging. Blooms reach about 0.13 feet (0.04 metres) across. NC State notes five petals and anthers with pale blue pollen. Plants bloom in spring and summer, though RHS lists summer alone. Bees visit the flowers. Gardeners can cut the stems for display.

Grow this flax in full sun and soil that drains well. NC State also allows partial shade, but favours full sun. Both sources list sandy and loamy soils as suitable. RHS advises light soil with humus and a moderate nutrient level. It accepts acid, neutral, or alkaline soil. NC State says plants cope with heat, humid air, and drought. Heavy clay can lead to shallow roots and poor winter survival. RHS assigns H4 hardiness; NC State lists USDA zones 4–9.

Use it in flower beds, informal borders, or cutting gardens. It also suits meadows and gardens meant to draw pollinators. Sow seeds where plants will grow in spring or autumn. Plants may self-seed where the site meets their needs. Cut some stems halfway back during bloom to help prolong flowering. Disease is seldom a problem. Aphids, slugs, and snails may attack. NC State says the seeds are poisonous to humans. They contain cyanogenic glycosides, which can make the throat swell or feel tight. Its poison rating is low. This does not mean it is safe to eat.